The USNS Comfort, the Navy’s East Coast hospital ship, has not been sent to provide hurricane relief in Puerto Rico. (Bill Mesta/Navy)

As the devastation from Hurricane Maria became more apparent Sunday, former Democratic presidential candidate Hillary Clinton implored President Trump and Defense Secretary Jim Mattis to help the people of Puerto Rico. Send the Navy, she tweeted, especially the hospital ship USNS Comfort.

President Trump, Sec. Mattis, and DOD should send the Navy, including the USNS Comfort, to Puerto Rico now. These are American citizens. https://t.co/J2FVg4II0n

Two days later, Federal Emergency Management Agency Director Brock Long announced that the Navy will soon do exactly that. The decision, disclosed in front of the White House on Tuesday afternoon, was later confirmed by the Navy. It comes after days of critics saying that the U.S. government isn’t doing enough to support hurricane relief in Puerto Rico, a U.S. territory of nearly 3.5 million people that faces months without electricity and a long rebuilding process.

Navy Cmdr. Mike Kafka, a service spokesman, said that the ship will leave within the next four days, and it will take up to five additional days to reach Puerto Rico. He called the move a “prudent decision in light of current conditions on ground.”

Clinton’s tweet lacked important context: The Navy already had two amphibious ships off the coast, the USS Kearsarge and the USS Oak Hill, so the few thousand Marines and sailors aboard could launch relief operations. But her call to action took off, with a petition on the website Change.org garnering more than 100,000 signatures in three days and critics expressing frustration with the hashtag #SendtheComfort.

Since then, the call for the Comfort has come to symbolize something larger: A call for the Pentagon to send more.

Trump described the U.S. government response to the devastation in glowing terms Tuesday morning, saying officials were “doing a really good job.” He plans to visit next week, once it is no longer a disruption to first responders, he said.

“It’s very tough because it’s an island,” Trump said. “In Texas, we can ship the trucks right out there. And you know, we’ve gotten A-pluses on Texas and on Florida, and we will also on Puerto Rico. But the difference is, this is an island sitting in the middle of an ocean. And it’s a big ocean; it’s a very big ocean.”

Facing growing criticism about its response, the Pentagon on Monday argued that its efforts over the weekend marked only the beginning. Army Col. Rob Manning, a spokesman, told reporters the U.S. military was focused near-term on search-and-rescue operations and delivering generators to hospitals. Other plans called for the arrival of eight Army Black Hawk helicopters from Fort Campbell, Ky., a fleet of Air Force jets arriving with supplies, and disaster-assessment teams determining what else is needed.

“This is a long-term effort,” Manning said. “It’s a marathon, not a sprint, so [the Department of Defense] will continue to support them as long as support is needed.”

The Pentagon’s effort is complemented by the U.S. Coast Guard, a part of the military overseen by the Department of Homeland Security. The sea service had 13 ships off Puerto Rico by Monday, and was working long shifts to fix ports and launch search-and-rescue missions.

The U.S. military provided a new list of other efforts related to Puerto Rico on Tuesday, noting that it had set up a staging base to deliver supplies at Dobbins Air Reserve Base in Georgia and delivered small numbers of troops from bases ranging from Fort Bragg, N.C., to Fort Stewart, Ga.

But the Navy’s presence was scrutinized. Thomas LaCrosse, the Pentagon’s director of defense support to civil authorities, said Monday that U.S. officials discussed sending the Comfort to Puerto Rico last weekend, but ultimately decided not to because ports were not ready to handle a ship that large after the storm.

The Comfort, homeported in Norfolk, is one of two hospital ships in the U.S. military, and the only one kept on the East Coast. The 894-foot vessel has beds for patients, 12 operating rooms and a flight deck for heavy-lift helicopters. It has been used following numerous natural disasters, including Hurricane Katrina in 2005 and the earthquake that devastated Haiti in 2010.

But LaCrosse and other defense officials argued that the situation this time was different. The Puerto Rican government did not ask for more Navy ships, but logistical support that includes getting its 60-plus hospitals up and running, LaCrosse said. In light of that, the Pentagon made the judgment call to send in a fleet of Air Force jets loaded with supplies and medical personnel beginning Friday, after the Army Corps of Engineers reopened Luis Munoz Marin International Airport in San Juan, he said.

Marine Corps Gen. Joseph F. Dunford Jr., chairman of the Joint Chiefs of Staff, told Senate lawmakers Tuesday that the military continues to respond to the crisis, with FEMA in charge. Air Force Gen. Lori J. Robinson, the chief of U.S. Northern Command, is making suggestions and recommendations along the way, he said.

“There’s literally hourly meetings between FEMA and the government officials in Puerto Rico, to make sure that we are doing all we can,” Dunford said. “The guidance from Secretary Mattis has been clear. What they need, they get. Just make it happen.”

Kafka, the Navy spokesman, said that the military actually was better positioned to respond to Hurricane Maria in Puerto Rico than it was during previous storms in the Caribbean islands. The Navy and Marine Corps already were working off the Kearsarge, Oak Hill and a third ship, the USS Wasp, to help following Hurricane Irma’s devastation there earlier in the month, and moved south out of Maria’s path before quickly returning, he said.

The size of Maria and its unpredictable course also may have played a role in how the U.S. military responded. The Navy had several ships, including the aircraft carrier USS Abraham Lincoln, providing hurricane relief off the Florida Keys. But commanders sent them back to port in Norfolk and Mayport, Fla., rather than leaving them off the east coast of Florida or in the Caribbean.

Still, the response and the characterization of it is in contrast with how the military responded to Irma in Florida and the Caribbean islands. In that case, the U.S. government deployed at least eight ships, and Tom Bossert, Trump’s homeland security adviser, described the effort as both “unprecedented” and “the largest flotilla operation in our nation’s history,” though more ships had been used in other similar operations in the past.

Rep. Adam Smith (Wash.), the ranking Democrat on the House Armed Services Committee, said Monday night that at minimum, Trump should establish a “coordinated military effort” overseen by a three-star general, a move that occurred after Hurricane Katrina and other disasters, such as a typhoon that hit the Philippines in 2013.

“The Trump administration’s response to the destruction in Puerto Rico has been wholly inadequate,” Smith said. “A territory of 3.5 million American citizens is almost completely without power, water, food, and telephone service, and we have a handful of helicopters involved in DOD’s response. It’s a disgrace.”